The missile can travel at double the previous model's range.
The UK first supplied Brimstone missiles to Ukraine about six months ago. Ukrainian troops have modified trucks to serve as mobile launch platforms for the missiles that are usually launched from the air.
The Brimstone's first version entered Royal Air Force (RAF) service in 2005. In 2008, it was upgraded to be guided by laser. The next model, Brimstone 2, entered service in 2016.
The UK Ministry of Defence recently said the country would shortly provide Ukraine with some 1,000 additional surface-to-air missiles.
Russia launched a special military operation in Ukraine on February 24 in response to calls by the Donetsk and Lugansk People's Republics for protection from Ukrainian troops. The Russian Defense Ministry said the operation, which targets Ukrainian military infrastructure, aims to "demilitarize and denazify" Ukraine, and to completely liberate Donbas.
Russian President Vladimir Putin has said the operation aims to "protect people subjected to genocide by the Kiev regime for eight years." Western nations have imposed numerous sanctions on Russia and have been supplying weapons to Ukraine.